The primary objective of this project is to quantify the effects of a commercially-available ambulatory electronic healthcare record (EHR) on quality of diabetes care, as measured by compliance with recommended processes of care and patient outcome measures, in a large group of primary care practices. The study will be conducted in the Baylor Health Care System (BHCS) HealthTexas Provider Network (HTPN) which includes 34 eligible primary care practices within its >100 practices, mostly with 10 or fewer physicians. HTPN began rolling out its EHR, staggered by practice, in May 2006. The primary aim is to test the short and long-term effects of the EHR on the care of diabetes patients in a naturalistic setting, as measured using the Health Partners Optimal Diabetes Care composite measure (HbA1c < 8%; LDL cholesterol < 100 mg/dL; Blood pressure < 130/80 mmHg; Aspirin prescription in patients e40 years; and, Not smoking). The study will use retrospective chart audit data on approximately 14,000 adult patients followed for up to 5 years through 10 successive semi-annual prevalence cohorts, collected using the American Medical Association (AMA) Physician Consortium Adult Diabetes Core Physician Performance Measurement Set. Secondary Aims will test the hypotheses that implementing an EHR will (1) change the proportion of patients meeting the recommended levels for each of the intermediate patient outcome measures (HbA1c, total cholesterol, LDL cholesterol, triglycerides, blood pressure); (2) change the proportion of patients in compliance with the individual recommended diabetes-related processes of care (HbA1c test, lipid panel, test for microalbuminuria, dilated retinal eye exam, complete foot exam, prescribed aspirin, influenza vaccination, smoking cessation counseling) collected in the AMA Physician Consortium Adult Diabetes Core Measure Set; and (3) be associated with clinically meaningful changes in the absolute levels of HbA1c level, cholesterol, triglycerides and blood pressure that may not be captured by the compliance with recommended levels measures. Additionally, as it is necessary to consider the availability and utilization of disease-specific functionalities, in addition to the overall presence/use of the EHR, in evaluating the impact on quality of care, this project will estimate the prevalence of voluntary physician use of the Diabetes Management Form embedded within the HTPN EHR, and the effect of Diabetes Management Form use on patient outcomes as measured by the Optimal Diabetes Care measure. Given the size of the study population and baseline performance data collected in the preliminary studies for the proposed project, we will have >90% power to detect a 6% absolute change in each the outcome measures within the Optimal Diabetes Care composite. This study will provide important information about the potential for an EHR to improve quality of diabetes care, including insight regarding the potential of and need for disease-specific EHR components to effect improvement.